Heartshape merger or overlap. 🙂

https://www.legacysurvey.org//viewer/?ra=147.9063&dec=11.2737&layer=ls-dr9&zoom=15

2 Likes

thats pretty

I’d go for an overlap. some disturbance so it’s close

SDSS spectra put them at z=0.102 and z=0.142, so I guess a coincidental overlap. Very nice though!

Maybe but there’s huge difference in recession velocities. The delta z CA. O.04 light speed represents about 12000 km per second!. That’s huge. I suspect that one or both z values is/are in error.
I still think they are close companions, gravitationally bond.

It is extremely rare to find an SDSS spectrum (with no warning flags set - ZWARN = 0) that is incorrect. These both look okay to me.

Lost a reply. The 0.0106 z HaS a lot of continuum noise.
It needs to be revisited, I’ve not seen it in zooniverse.org.I still think it’s a close group association, IE. Within a fraction of a megaparsec.
This is entered with my smartphone and not my other laptop or mainframe

Apologies for syntax errors etc.

LAMOST has taken spectra of both components and determined redshifts of ~0.101 & ~0.142. I think we’re safe in assuming these values are accurate.

As it happens, its definitely been on GZ on Zooniverse. Its in a bunch of galaxy zoo tables in vizier.

I’m afraid you aren’t aware of the implications. The delta z difference according to the Doppler shift of wavelengths , amounts to 4% of the speed of light. Given a Hubble Constant of 70 km/second/megaparsec the separation is 171 megaparsec , or the galaxy overlap in the background is at 558 million light years more distant. For example this is more than 200 fold the distance between our galaxy and M31 Andromeda.!
Perhaps one could contact LAMOST and query the visual evidence.

LAMOST J095136.06+111601.5 – Galaxy I think you have misidentified the overlap with the galaxy in the same group to the SE.

LAMOST J095136.06+111601.5 – Galaxy
Other object types: G (2018MNRAS)
ICRS coord. (ep=J2000) : 09 51 36.065 +11 16 01.54 (Optical) [ ] D 2018MNRAS.474.1873W
FK4 coord. (ep=B1950 eq=1950) : 09 48 55.106 +11 30 07.36 [ ]
Gal coord. (ep=J2000) : 224.555905 +44.968547 [ ]
Radial velocity / Redshift / cz : V(km/s) 39167 [~] / z(spectroscopic) 0.140421 [~] / cz 42097.16 [~]
(Opt) E 2018MNRAS.474.1873W

Fluxes (5) : u (AB) 20.846029 [~] D 2018MNRAS.474.1873W
g (AB) 18.337870 [~] D 2018MNRAS.474.1873W
r (AB) 17.214970 [~] D 2018MNRAS.474.1873W
i (AB) 16.745640 [~] D 2018MNRAS.474.1873W
z (AB) 16.433060 [~] D 2018MNRAS.474.1873W

the #lsb to the north
SDSS J095139.79+111806.7 – Galaxy
Other object types: G (2018ApJ,AGC), HI (ALFALFA)
ICRS coord. (ep=J2000) : 09 51 39.793 +11 18 06.71 (Optical) [ 410 391 0 ] C 2009ApJS…182…543A
FK4 coord. (ep=B1950 eq=1950) : 09 48 58.815 +11 32 12.67 [ 410 391 0 ]
Gal coord. (ep=J2000) : 224.522070 +44.998014 [ 410 391 0 ]
Radial velocity / Redshift / cz : V(km/s) 3199 [~] / z(emission) 0.010728 [~] / cz 3216.25 [~]
(Rad) D 2018ApJ…861…49H

Fluxes (5) : u (AB) 19.554 [0.128] E 2009ApJS…182…543A
g (AB) 18.216 [0.031] D 2009ApJS…182…543A
r (AB) 18.024 [0.031] D 2009ApJS…182…543A
i (AB) 17.962 [0.066] D 2009ApJS…182…543A
z (AB) 18.339 [0.146] E 2009ApJS…182…543A

I haven’t misidentified anything. I’m definitely talking about the correct galaxies. The two LAMOST galaxies I am referring to are ~1 arcsec from eachother.

J095137.70+111627.8 - Redshift: 0.1010980000
J095137.34+111628.9 - Redshift: 0.1419530000

These are consistent with the SDSS results. 2 spectroscopic surveys with extremely similar values. Neither have any flags. The odds of both being wrong somehow are astronomical (if you’ll pardon the topical pun).

But hey, if you want to check the spectra for yourself, the SDSS spectra are accessable through the viewer on this site & the LAMOST spectra are viewable in vizier.

These values are not extremely similar. They are vastly different
Certainly values, numerical 0.10.… and O.14……appear to be close compared with 0…10…100 to infinity,but in astrophysical measure they imply a separation of ca. 580 million light years. This distance is greater than galaxy groups, clusters and super clusters. It’s called a cosmological distance, across a Great Wall

Hi Graham,

I’m not sure what your point is. The redshifts indicate that these galaxies are not close to each other in our line-of-sight direction. They’re not interacting, they just happen to be overlapping on the sky. At least that’s my interpretation.

cheers,
dustin

I meant that the values from SDSS are extremely similar to the values from LAMOST. Not that the redshifts of two galaxies are similar.

I’m also not sure what your point is. Two independant spectra of each have shown that they’re not related.

Chance alignment happens quite a lot. Its a big universe. Bearing in mind that the further galaxy is only around 40% more distant than the near one, the apparent sizes of the galaxies make sense.